Science Musings Blog

Friday, August 27, 2010

Earth time, human time

Walking the nearby wild Atlantic coast we came upon this pile of rocks. How long it had been there I have no idea, although it is hard to imagine it holding up to the wind for long. Some person or persons with a sense of whimsy clearly sought to assert creativity in the face of the elements. Very Andy Goldsworthyesque.

Reversing, if only briefly, the wreck of worlds.

This bit of coast is made up of Silurian siltstone, with some volcanics, 425 million years old, or thereabouts, from a time when an older "Atlantic" Ocean, the Iapetus, was closing up. We have found trilobite fossils in these rocks, small ones, and inch or two in length -- they scratched out an existence on the shallow sea floor as volcanic islands rose up around them. A crush of continents!

A vast new supercontinent was forming, the Old Red Sandstone Continent -- one could have walked dry-shod from our house in Ireland to our home in New England. I have told the story before, in Honey From Stone, of the role these rocks played in the development of mid-19th-century geology. Richard Griffith, Joseph Beete Jukes, James Flanagan, George Victor Du Noyer, and even the great Roderick Murchison, scrambled along this shore trying to sort out the history of the planet, gaining a sense of the eons of time that Charles Darwin would soon fill up with the history of life. When I walk these cliffs I never fail to think of those eminent men in their top hats and frock coats standing here (no doubt in the rain) where we stand, passing fossiliferous stones from hand to hand, furiously debating their meaning.

Mountain ranges ground to dust, lifted out of the sea, then pulverized again. The rubble of former worlds. And here some light-hearted soul has sought to reverse the arrow of entropy, with a structure even more ephemeral than that of the other anti-entropic creature who has volunteered to provide a sense of scale.